We previously reported that the U.S. Patent and Trademark Office (“PTO”) granted two PTEs with respect to two patents following FDA’s December 4, 1997 approvals of NDAs for OMNICEF. One PTE was for U.S. Patent No. 4,559,334 with respect to NDA No. 50-739 for OMNICEF Tablets. Another PTE was for the ‘507 patent with respect to NDA No. 50-749 for OMNICEF Oral Suspension. As we discussed in our previous post, the PTE statute states (at 35 U.S.C. § 156(c)(4)) that “in no event shall more than one patent be extended . . . for the same regulatory review period for any product.” The PTO interprets 35 U.S.C. § 156(c)(4) to permit multiple PTEs under certain circumstances – specifically, for a drug product covered by several patents the PTO may extend a different patent for each NDA approved on the same first day (even when multiple NDAs share common “testing phase” and a “review phase” dates). That is, the PTO considers each NDA “regulatory review period” to be distinct and for which a PTE is available.

There are only a few cases in which the PTO has granted or companies have been eligible for multiple PTEs for different patents covering the same product approved under separate NDAs on the same first day. For example, in addition to OMNICEF, the PTO has granted multiple PTEs for LYRICA (pregabalin) – one for U.S. Patent No. 6,001,876 with respect to NDA No. 21-723, and another for U.S. Patent No. 6,197,819 with respect to NDA No. 21-446. FDA also approved two NDAs on the same first day for MYCAMINE – NDA No. 21-506 for MYCAMINE for prophylaxis of Candida infections in patients undergoing hematopoietic stem cell transplantation, and NDA No. 21-754 for MYCAMINE for the treatment of esophageal candidiasis. In that case, the NDA sponsor applied for two PTEs based on these approvals – one for either U.S. Patent Nos. 5,376,634, 6,265,536, or 6,107,458 for NDA No. 21-506, and one for either of these same patents for NDA No. 21-754 – but ultimately decided not to elect a second PTE. More recently, FDA approved two NDAs on the same first day for VIMPAT (lacosamide) – NDA No. 22-253 for VIMPAT Tablets and NDA No. 22-254 for VIMPAT Injection – and the NDA sponsor is seeking a PTE for different patents with respect to each NDA approval (see PTE applications here and here).

Lupin argued as part of its ‘507 patent infringement case in the U.S. District Court for the Eastern District of Virginia that “[t]he issuance of two PTEs for regulatory review periods involving cefdinir as the active ingredient was not authorized under 35 U.S.C. § 156,” and requested that the court declare the ‘507 patent PTE invalid. However, Abbott and Lupin later entered into an agreement (a Stipulated Order of Dismissal) concerning the ‘507 patent. As part of that agreement, Lupin’s claim concerning the PTE for the ‘507 patent was dismissed without prejudice. However, the Stipulated Order of Dismissal also stated that Lupin may reassert that claim in the event that the court’s final judgment on other claims in the litigation are not affirmed, and are remanded, on appeal. The Federal Circuit in Abbott Labs. v. Sandoz, Inc. affirmed that the “Eastern District of Virginia properly concluded on summary judgment that Lupin’s cefdinir product did not infringe” certain claims in the ‘507 patent. Given this ruling, Lupin will not need to reassert its claim that the PTE for the ‘507 patent was invalid.